1. Field of the Invention
The present invention relates to a cultivation of Paecilomyces sp.(Chinese name; Tochu-kaso) using silkworm as a host. More particularly, it relates to a cultivation of Paecilomyces sp. which comprises steps of inoculating Paecilomyces sp. into larvae of silkworms and inducing a fruitbody of Paecilomyces sp. therefrom
2. Description of the Related Art
Tochu-kaso is a parasitic living fungus on larvae and pupae of insects. Some of them had been used for the medicinal purpose, and are distributed in many countries, for instance, China, Nepal, Japan, South America, Republic of Korea, etc.
A typical infection route of Tochu-kaso is an epidermal infection wherein its conidia are scattered and adhered to an epidermis of a host insect. The adhered conidia are germinated under appropriate temperature and humidity conditions, and penetrates into a body of the insect. And then, its spawn grown within the interior of the insect body induces a fruitbody on the epidermis of insect. The infected insects died.
Its fruitbody consists of petiole and a fruit portion at an end thereof and has a size of 1.5.about.10 cm. Further, it has filiform, clubbed or cylindrical shapes and various colors such as white, black, red, brown etc., depending on the species.
Tochu-kaso has been known as a medicinal fungus having pharmacodynamic efficacy against various diseases. For example, in China, it has been mentioned as a secret medicine for eternal youth. In addition, it has been reported that it protects the lung and enhances the functioning of the kidney. Further, the "Jungrubonso", Chinese old pharmacopeia, says that various species such as Yongchuso and Ahyangbongchuso are efficacious against various diseases. Also, in Japan, "Bonsosu" (1801) says that Tochu-kaso was sold as a miracle drug against a lung disease and pleurisy.
Recently, many studies have been conducted in order to evaluate pharmacodynamic efficacy of Tochu-kaso shown in these old pharmacopeia. As a result, it was reported that its extract contains substances capable of reinforcing immune system and thereby can promote cellular and humoral immunities and improve a resistance against various tumors and viruses.
A clinical test conducted in Switzerland reported an example wherein a two weeks by administration of extracts of Tochu-kaso into a drug addict patient can protect him from the temptation and adverse effects of the drug. Further, the patient eventually returned to normalcy.
It has also been known to have effectiveness of alleviating fatigue and stress.
Due to various efficacy, many studies have been and are being conducted on Tochu-kaso in order to incorporate its extract into pharmaceutical compositions or drinks. Although 300 or more species are distributed all over the world, due to its small size and lower distribution density compared with the other fungi or medicinal plants, there is a difficulty in obtaining absolute amount required for the establishment of its pharmacological efficacies and a clinical test. In addition, since its efficacy varies largely depending on the species, this difficulty is so much the worse.
Under this circumstance, the present invention studies have been focused on the cultivation thereof. Firstly, they have got informations from the studies on Tochu-kaso species inhabiting in the nature, its host insects, a route of infection and conditions of inducing fruitbody. And then they make a setting of an appropriate host insect and cultivation conditions.
On basis of these informations, they could establish characteristics of Tochu-kaso species.
The present invention is also accomplished as a results of the same research.
Above all, the present inventors selected silkworm as a host insect in the cultivation since its rearing method is well established. Further, since silkworm itself has been used as a medicine stuff, it is believed to be more preferably used as a host insect. Then, they have conducted in order to find Tochu-kaso strains able to use silkworm as a host insect.
As a result, they found that Paecilomyces sp. can use silkworm as a host.